Magnetic solid‐phase extraction of organophosphorus pesticides from apple juice and environmental water samples using magnetic graphene oxide coated with poly(2‐aminoterephthalic acid‐co‐aniline) nanocomposite as a sorbent

An effective magnetic solid-phase extraction method was proposed using magnetic graphene oxide coated with poly(2-aminoterephthalic acid-co-aniline) as a sorbent for preconcentration and extraction of organophosphorus pesticides from environmental water and apple juice samples, and determined using the gas chromatography-mass spectrometry analysis. To approve the successful synthesis of the magnetic nanocomposite, the prepared sorbent was characterized by field emission scanning electron microscopy, X-ray diffraction, vibrating sample magnetometer, and Fourier transforms infrared techniques. The main parameters affecting the extraction efficiency were considered and studied to afford an optimized procedure. Systematic method validation verified its suitable recoveries (89.4%-107.3%), and precision (relative standard deviations < 6.8%). The method showed a wide linear dynamic range (0.04-700 ng/ml) with low limits of detection (0.01-0.06 ng/ml) and quantification (0.04-0.21 ng/ml). This method presented good potential and great sensitivity for the pesticides determination.